Wednesday, February 29, 2012

The Lyman Alpha Mapping Project (LAMP) on the Lunar Reconnaissance Orbiter (LRO) mission is seeking a postdoctoral planetary scientist to join our team's investigations of a variety of lunar science questions using far-UV observations of the lunar surface.

Topics of study include characterization of permanently shaded regions at the lunar poles, mapping of surface water frost and hydrates, and identifying regional space weathering effects. The far-UV map and spectra analyses to be performed include comparisons with other LRO and lunar datasets for detailed surveys of regions of interest. Applicants having experience with imaging and/or spectroscopy from space-based observations, and a background in scientific analysis and publication of lunar geology and/or volatiles topics are encouraged to apply. This is a one year limited term position in San Antonio, TX, with extension dependent on availability of funding.

Fractures at the edge of an impact melt pool within the crater Larmor Q. Field of view 312 meters across from the LROC Featured Image, February 29, 2012 (540 meters), LROC Narrow Angle Camera (NAC) observation M151726155R, orbit 7494, February 7, 2011; 0.57 meters per pixel from 54.8 kilometers altitude [NASA/GSFC/Arizona State
University].

The crater Larmor Q, located at 28.630°N, 176.240°E, is 18.3 km in diameter, has slumped walls, and impact melt in its floor. The Featured Image show fractures within this impact melt at the boundary of boulder-rich slumped material and the impact melt pool itself. The fractures may have formed two ways: from post-impact modification of the crater floor, or from a volume change associated with the cooling of the impact melt. Post-impact modification means that the shape of the crater changed, due to slumping walls, or changes in the crater floor topography caused by strain due to the redistribution of material during the impact itself.

The fractures are closer together (denser) near the edge of the impact melt. This may be where the impact melt is the thinnest, depending on the topography of the crater floor. Imagine an empty bowl (the crater) and then fill the bottom 5% of the bowl with ketchup (impact melt). The ketchup will be shallowest closest to the sides of the bowl. Often impact melt pools are not of uniform thickness due to variations in the shape of the crater's floor. Also, within the same crater there may be multiple impact melt pools of different overall depths since the emplacement of melt is not symmetric with respect to the crater.

When a lava (or impact melt) cools, it reduces in volume, which may have formed these cracks. Or, the thinnest part of the impact melt might be expected fracture more in the case of changes in the floor topography. Lunar scientists will have to study fractures in impact melt pools to determine which of these answers is correct. Perhaps it is a combination of the two causes of fractures, or something not yet considered.

LROC Wide Angle Camera (WAC) image of the 18.3 km diameter crater Larmor
Q. Slumping of the crater walls has not yet covered all the impact melt
on its floor. From LROC WAC observation M136389155 (604nm), orbit 5233, August 14, 2010; angle of incidence 54.83° with a resolution 82.1 meters per pixel from 58.4 kilometers [NASA/GSFC/Arizona State University].

Find other areas in Larmor Q where fractures are denser towards the edge of the impact melt in the full NAC frame!

Project Morpheus used to be called Project M, and it was an ambitious plan to send a Robonaut to the moon in under 1,000 days by embracing efficiency and cooperation while avoiding bureaucracy as much as possible. We've been huge, huge fans of the project ever since its manager, Matt Ondler, defended the idea to a seemingly uninterested NASA in an impassioned blog post that ended with "we will continue to push back the darkness until they chain the doors and take away our hacksaws."

We were completely sold, of course.

That was back in July of 2010, and since then Robonaut has ended up on the International Space Station, and Project M has (for better or worse) morphed into Project Morpheus, a vehicle designed to transport a robot (or anything else) to the lunar surface. Just two days ago, Morpheus underwent a test firing of its brand new engine.

Preliminary LRO (DVNR) thermal (Channel 8) imagery revealed the lunar surface inside the permanently shadowed regions (PSR's) of the Moon's polar regions and aided in the choosing of Cabeus as the prime target for the LCROSS impact. Since then, LRO has orbited the Moon over the poles 13000 times and returned more data to Earth than all other deep space missions combined, a treasure trove requiring years to analyze [NASA/GSFC/UCLA].

See http://diviner.ucla.edu for more information. Applicants with a background in planetary surfaces, remote sensing, computer science, large datasets, parallel computing, Fortran, and Unix are encouraged to apply.

The initial appointment is a full-time 1-year appointment beginning as early as April, 2012 with an expectation of continuation depending on progress and availability of funding.

Applicants should send a CV with a list of publications, addresses and e-mail addresses of at least 2 references, and a one page summary of current research to Professor David A. Paige - dap@moon.ucla.edu.

The University of California is an Equal-Opportunity/Affirmative Action employer

Tuesday, February 28, 2012

Tentative 'hard' evidence of 'late heavy bombardment' and lunar cataclysm surmised
by NLSI team may have resulted from a shift in the positions of the outer planets "late" in the early history of our star system's formation, throwing smaller rocky airless bodies into new trajectories and raining into the inner solar system. Post-Lunar Cataclysm diagram of the Solar System
[LPI/Marchi/Bottke/Kring/Morbidelli].

A team of NLSI researchers have discovered that debris that caused a "lunar cataclysm" on the Moon 4 billion years ago struck it at much higher speeds than those that made the most ancient craters. The scientists found evidence supporting this scenario by examining the history of crater formation on the Moon.

During Earth's earliest days, our planet and others in the inner solar system, including the Moon, experienced repeated impacts from debris that formed the building blocks of the planets. Over time, as material was swept up and incorporated into the inner planets, the rate of impacts decreased. Then, roughly 4 billion years ago, a second wave of impacts appears to have taken place, with lunar projectiles hitting at much higher speeds. This increase could reflect the origin of the debris, where main belt asteroids were dislodged and sent into the inner solar system by shifts in the orbits of the giant planets.

The team is composed of Simone Marchi, an NLSI postdoctoral fellow, William Bottke, the NLSI Team Lead at Southwest Research Institute, Columbia, Md., David Kring, the NLSI Team Lead at USRA's Lunar and Planetary Institute in Houston, and Alessandro Morbidelli from the Observatoire de la Cote d’Azur, France. Their research paper, “On the Onset of the Lunar Cataclysm as Recorded in its Ancient Crater Populations,” was recently published in the journal Earth and Planetary Science Letters.

Nectaris basin, surrounding impacts of the same age and size may have formed from progenitors traveling at a higher velocity than elsewhere [NASA/LMMP].

The scientists analyzed digital maps of the lunar surface to learn about its history. Their analysis shows that craters formed near the 860 km diameter Nectaris impact basin were created by projectiles hitting twice as fast as those found on more ancient terrains. This was represented by a subtle shift in crater sizes, with the crater themselves thirty to forty percent larger on average than those found in comparable populations with older craters. The scientists believe this can be best explained by an increase in the velocities of the projectiles that produced the younger craters.

The increase in velocities may indicate a change in the solar system when the craters were created. The analysis supports the "lunar cataclysm" hypothesis that the brief pulse of impacting objects 4 billion years ago was due to gravitational disturbances caused by the reorganization of the giant planets as their orbits changed. Nectaris, a crater close to the Apollo 16 landing site, appears to have recorded the spike in asteroid impacts during the "lunar cataclysm."

Determining the magnitude and duration of any impact cataclysm and testing that hypothesis is a top science priority for future exploration of the Moon, according to Scientific Context for the Exploration of the Moon(2007) by the National Research Council's Space Studies Board.

When Apollo astronauts gathered rock samples from the Moon, many samples had ages dating back 3.9 to 4 billion years ago, suggesting an enhanced pulse of bombardment. If a bombardment of asteroids hit the Moon as theorized, there could be indicators left on the lunar surface that would help validate the theory. Detailed mapping by the United States Geological Survey has previously identified small regions of the lunar surface that might contain clues about the bombardment. The team re-studied those ancient surfaces and measured the sizes of the impact craters using new data obtained from the Lunar Orbiter Laser Altimeter, an instrument on NASA’s Lunar Reconnaissance Orbiter (LRO) currently orbiting around the Moon.

“This is an exciting time for lunar research with LRO and other spacecraft providing so much new data,” said lead author Simone Marchi. “Collaborating with scientists of different disciplines allowed us to link these observational data to dynamical models to put new constraints on solar system history.”

The inferred increase in velocity seems to have occurred after the Moon’s largest impact basin was produced, the 2,500-kilometer-diameter South Pole-Aitken Basin, but before the formation of the largest lava-filled impact basins on the lunar nearside, visible from backyards around the world.

“It is fascinating that the surface of our own Moon records evidence of orbital changes in Jupiter and Saturn that took place so long ago,” said NLSI Director Yvonne Pendleton.

The onset of the lunar cataclysm as recorded in its ancient crater populationsEarth and Planetary Science Letters, Volumes 325–326, 1 April 2012, Pages 27-38
Simone Marchi, William F. Bottke, David A. Kring, Alessandro Morbidelli

Astrobotic Technology will launch its first expedition on a Falcon 9 rocket under contract from Space Exploration Technologies (SpaceX).

In May 2015, it will deliver a robot to the Moon’s south pole to prospect for water, methane and other minerals. Turned into rocket propellant, these resources will dramatically reduce the cost of space exploration by providing an off-planet refueling station.

“The number one challenge in space exploration today is the cost,” said David Gump, Astrobotic’s president. “Commercial robotic expeditions can serve space agencies at one-third the cost they traditionally spend with cost-plus contractors. And by prospecting for rocket fuel ingredients at the Moon’s poles, we can provide a much lower cost source for spacecraft propellant as they venture further away from Earth.”

Notional field array of 30-meter (short wave) antennae deployed on the lunar surface, beyond the effects of Earth's dynamic ionosphere, which is notoriously refractive of radio waves to HF wavelengths [NLSI].

The lunar surface is often identified as a prime location for acquiring radio observations at frequencies below the terrestrial ionospheric cutoff or for lunar far-side observatories that would be shielded from terrestrial radio interference. We consider a candidate observatory for solar radio burst imaging below 10 MHz.

The Radio Observatory on the Lunar Surface for Solar studies (ROLSS) consists of 3 arms of thin polyimide film, each 500 meters in length and radiating from a central hub, providing approximately 2 degrees angular resolution at 30-meters wavelength (10 MHz). Each arm includes 16 dipole antennas consisting of metal deposited on the film and transmission lines connecting to receivers at the central hub. These arms could be unrolled using a crewed or robotic rover.

The data collected by the antennas are processed at the central hub and down-linked to Earth for final radio image synthesis. This antenna system is uniquely suited to the low mass and low volume requirements for delivery to the lunar surface.

In an online presentation sponsored by the NASA Lunar Science Institute, Feb. 28, Robert MacDowell of NASA Goddard reviewed the scientific goals of ROLSS and their relationships to heliophysics, hardware components ROLSS requires, the current status and work to be completed and the role of a pathfinder mission to provide mission risk reduction at modest cost.

The ROLSS concept study was funded by the NASA Lunar Sortie Science Opportunities (LSSO) program. The LUNAR consortium (Jack Burns, P.I.) is funded by the NASA Lunar Science Institute to investigate concepts for astrophysical observatories on the Moon.

Robert MacDowall has worked at NASA Goddard Space Flight Center (GSFC) since 1979, originally as an employee of Computer Sciences Corporation and other contractors, and later as a civil servant. During his years at Goddard he has worked in the fields of solar and planetary radio astronomy, in analyses of the solar wind and interplanetary magnetic fields, and plasma wave physics. He is currently the Lab Chief for the Planetary Magnetosphere Laboratory.

Monday, February 27, 2012

The Planetary Science Section at JPL, based in Pasadena, CA, is looking to fill two positions for researchers in areas relevant to future Martian sample return missions. The first position is for study in the area of mineralogy, petrology and/or meteoritics. The research is expected to further knowledge of petrogenetic processes throughout the Solar System. Advanced scientific knowledge of petrology, mineralogy, and/or meteoritics is expected. The ability to use analytical and theoretical approaches to solving problems related to the origin and evolution of igneous rocks and/or extraterrestrial samples is essential.

The second position is for a researcher within the area of organic geochemistry with a strong focus on geobiological and/or astrobiological investigations. The researcher will possess expertise in those areas related to the origin and significance of organic material in terrestrial and extraterrestrial geological samples. Themes of study are expected to include the origin and evolution of life on Earth, the study of extraterrestrial organic compounds, and/or the recognition of biosignatures in returned Solar System samples.

It is expected that both positions will pursue new mission and/or instrument opportunities through advocacy and outreach within the scientific and stakeholder community. This pursuit will involve working closely with science and engineering teams at JPL to design Solar System sample return and planetary exploration missions and instrumentation. The candidates are expected to have a PhD along with advanced knowledge and demonstrated experience in conceiving, defining, and conducting independent scientific research. Both positions include significant start up packages. Both positions offer a competitive salary and impressive benefits with a renowned leader in Planetary Science.

To view the full job descriptions and apply to these positions, please visit: http://careerlaunch.jpl.nasa.gov, (see Requisitions #10654 and #10655). Applications will be reviewed as they are received, and should include a curriculum vitae, a career statement with research objectives and contact information for three professional references. JPL/Caltech is an equal opportunity/affirmative action employer.

In the absence of an absolute age date, lunar scientists have to rely on the geomorphology of a crater to determine how old it is relative to other craters. The sharpness of the deposits in today's Featured Image is a good indicator that Moltke is young, probably Copernican in age. Large cracks in the impact melt formed as the melt cooled and contracted towards the center of the crater. The uneven terrain within the melt is probably composed of smaller ejecta blocks that have been mixed in with the impact melt. These features have not been covered by regolith or debris flows from the crater wall that naturally accumulate over time, indicating that Moltke is probably young. Do these observations agree with a larger contextual view?

Context for the LROC Featured Image (FOV yellow arrow). Moltke (0.589°S, 24.180°E) is barely 6 kilometers in diameter but has a diffuse high-reflectance ejecta blanket that makes it very easy to spot in modest telescopes trained in on the south-southeastern corner of Mare Tranquillitatis, nestled between the craggy "horns" of the contact separating the relatively flat Sea of Tranquility. This makes it easy to spot, at least in the mind's eye, the spot where "man first walked upon the Moon, July 20, 1969, a very little distance to the northwest. LROC Wide Angle Camera (WAC) observation M144463675CE, orbit 6463m November 15, 2010; resolution 62 meters from 45.07 kilometers [NASA/GSFC/Arizona State University].

These observations do agree with the larger contextual view! A bright halo of ejecta surrounds Moltke, superposing older and darker mare material. The "freshness" of the impact melt and crater wall, the brightness of the ejecta blanket all argue that Moltke must be a relatively young Copernican aged crater.

Sparely labeled HDTV frame of the southwestern corner of Mare Tranquillitatis, landing site of Ranger 8, Surveyor 5 and Apollo 11, as captured by Japan's lunar orbiter SELENE-1 (Kaguya) and released November 2009. View an enlarged version HERE [JAXA/NHK/SELENE].

The dry debris flows in the context of the western side of Moltke crater were also imaged from LRO during the brief and extraordinary low-periapsis maneuvers, on August 15, 2011, from only 24.96 kilometers altitude; with resolution of 40 centimeters. Those unique unprocessed frames are M168048451L and M168048451R.

Marc Boucher at SpaceRef has posted a "free preview from the March issue of Space Quarterly magazine," an article "only available in the U.S. edition."

Lunar bases and their location is a subject that has been discussed and argued about for decades, without any real consensus, because each interest group is driven to a different area. Some think little of the Moon and see it as nothing more than a distraction on the way to Mars. The thesis of this article is that not only is the Moon vitally important for developing a sustainable infrastructure to support the eventual settlement of Mars, it is vitally important for the overall future of mankind and for the economic development of the solar system. It is far beyond time for our community to make this intellectual commitment and then develop our thoughts and plans from there. In order for mankind to prosper on the Earth in the long term, the resources of our solar system, beginning at the Moon, are crucial, and it is time to quit apologizing for this stance. To provide structure three general regions of interest will be discussed, based upon utility, cost, and long-term viability.

Nick Azer, author of the Luna C/I (Colonization and Industrialization) blog and now an official part of the LPI's MyMoon Street Team, has been busy, "running down the Best of the Best, 'fashion-wise,' of the competing Google Lunar X-Prize lunar rovers.

"The $30 million Google Lunar X PRIZE has 26 teams competing for the prize - each with their own rover, and each jockeying for the adoring love of the space community.

"Each rover, lander, hopper, ball, and other budding moon explorer has different functionality, but their own brand of robochique. The best rover may win but the foxiest will walk away with the style points.

"To that end, I'll be rolling out each of the 26 teams' rovers onto the catwalk for the ultimate in wheeled robotic fashion shows! Bundle up and brace yourself for a whirlwind tour of the finest Mr. and Mrs. Moons Luna will have to offer circa 2015."

Dover, New Hampshire: Children were treated to an out-of-this-world engineering experience by members of the University of New Hampshire lunar robotics team, LunaCats, who demonstrated one of their creations at the Dover Childrens Museum.

The LunaCats design and build robotic excavators intended to mine lunar soil for a NASA competition. This year's team is comprised of seniors in the mechanical engineering, computer sciences, and computer engineering majors. As part of the competition, NASA mandates each team create an outreach program, benefiting the local community and the demonstration at the children's museum was part of that.

"I think the best part is that it's hands-on," Camille Poulin, student, said as she stood Monday afternoon surrounded by parents, children and her peers all watching as youngsters took turns operating the machine, the end result of a yearlong project.

The first half of the school year consists of designing and analyzing the excavator. The second half is dedicated to building and testing the machine.

Students brought last year's model to the museum on Monday and said they are completely redesigning the bot for 2012.

The seven students fund raise to both create the excavator and enter the competition, coordinating everything from funding, to the initial design, to travel to compete. They'll also complete a systems engineering paper and a presentation before NASA officials. The winning team will be awarded a $5,000 scholarship.

Last year, the 2010-2011 UNH LunaCats team was the first team from UNH to compete in the NASA Lunabotics Mining Competition. The team was unable to finish the competition due to an unforeseen mechanical failure involving the drive train, which caused limited mobility.

The LunaCats design and build robotic excavators intended to mine lunar soil for a NASA competition. This year's team is comprised of seniors in the mechanical engineering, computer sciences, and computer engineering majors. As part of the competition, NASA mandates each team create an outreach program, benefiting the local community and the demonstration at the children's museum was part of that.

Wednesday, February 22, 2012

A step is situated here, in between a small crater's floor and rim. The crater
also displays a high density of boulders on its surface. LROC Narrow Angle Camera (NAC) observation M122700360L, orbit 3216, March 8, 2010; incidence angle 56.8° over a field of view 330 meters across, resolution 0.48 meters from 40.6 km. View the larger LROC Featured Image HERE [NASA/GSFC/Arizona State University].

Today's Featured Image focuses on an 800 meter crater in northern Oceanus Procellarum, at 48.527°N, 285.939°E.

A crater this small is normally considered a simple crater, but this crater has what looks like a terrace! Terraces are normally found in complex craters, but some simple craters do form benches.

Strength differences in buried rock layers encountered during the impact are probably the cause of such benches. Zooming out and looking at the crater in context may give us a better understanding of whether this is a bench or terrace.

Context image of the Featured Image, FOV within the box. The
image above has been subsampled to 1.5 m/p and the larger image FOV is 1500 meters; LROC NAC
M122700360L. View the larger, original context image HERE [NASA/GSFC/Arizona State University].

The context image reveals that the terrace doesn't circle the entire crater, similar to how complex craters contain multiple unconnected terraces. But the crater is also very blocky, it probably hit a cohesive layer of basalt hidden under a layer of regolith, so maybe it is a bench. Whichever hypothesis is correct, the Moon is definitely not so simple!

Further context from the NASA ILIADS (LMMP) application. Even as vast an expanse as Oceanus Procellarum has an end, in this case a 2500 meter high boundary between highlands and the Procellarum basin's northwest. The small crater, spotlighted in the LROC Featured Image and designated with a yellow arrow, is situated on mare-inundated terrain roughly 2200 meters below the Moon's mean elevation. Beyond the high mountains (at heights near or only slightly above mean elevation) is the complex heart of the Repsold and Rimae Repsold formation. The floor of Repsold is 500 meters higher than the Procellarum basin floor. LROC Global 100 meter monochrome Wide Angle Camera mosaic overlaid upon LOLA laser altimetry at 128 points per degree (v.2) [NASA/ILIADS/LMMP/GSFC/Arizona State University].

The second annual Lunar Superconductor Applications Workshop (and other cold temperature technologies and science opportunities for the lunar polar regions) will be held March 15 and 16, 2012, at the Woodlands Waterway Marriot Convention Center (the same hotel as the LPSC) in Houston. Topics include high temperature superconductivity, low temperature power and electronics, cryogenic engineering and lunar science. Formal presentations are interspersed with informal design challenge discussions throughout the meeting. See more details on the website www.lsa2012.com

The single most important discovery in Lunar science is the confirmation of icy volatiles at the Lunar poles. This not only makes the Moon an exciting destination in its own right, but the Lunar poles are a Rosetta Stone for cryogenic chemistry and physics throughout the solar system and beyond.

Located in a back corner of the company’s building on Bleams Road, the team quickly filled its first work area with gears, tangles of exposed wiring, and metal pieces that might have been from a giant puzzle. They expanded into another workshop, then filled that one too.

The deadline to produce a high-tech rover is six months away. The project, called Artemis, also spawned a robotic offspring when ODG was contracted to build another smaller rover. That project has been nicknamed “Artemis Junior” by ODG’s space and robotics manager Peter Visscher.

And while the project’s ambitions have grown, the rovers themselves have got smaller. ODG’s first rover prototype, built in 2010, weighed 650 pounds. Visscher and his team have cut that down by building with titanium, which is a third of the weight of steel.

But it’s also more expensive, and the rovers are getting more complicated as new features are added.

The Artemis rover is designed by ODG’s team to be an all-purpose tractor for moon exploration. It could carry astronauts or equipment, or move across the moon’s cold surface by remote control.

Tuesday, February 21, 2012

A small fresh crater positioned right on the rim of Hermann B (0.35°S, 302.832°E).
Material slides down the crater wall toward the crater center, creating
small headscarps along the interior's rim. Image width is 650 m, LROC Narrow Angle Camera (NAC) observation
M117867678RE, orbit 2503, January 11, 2010; field of view 650 meters from an original resolution of 0.68 meters per pixel from an altitude of 42.54 kilometers. See the 1000 x 1000 full size LROC Featured Image HERE [NASA/GSFC/Arizona State University].

Crater rims are a boundary between the inside and outside of a crater. Thus the rim is also where the slope changes from steeply down into a crater to the shallow sloping exterior.

This change in slope results in a ridge along which dry debris flows often form and carve backwards into the rim. This fresh crater is almost on top of the rim of Hermann B, so what does the whole crater look like?

A context image might give us an idea.

Context image for the Featured Image (white box), centered on 0.353°S, 302.830°E.
The rim of the young crater is almost touching the rim of Hermann B.
The interior of Hermann B is to the left with the exterior is to the
right in this mosaic of the left and right frame pair for LROC NAC
M117867678, subsampled to 2 meter/pixel. View the full size context image accompanying the Featured Image release HERE [NASA/GSFC/Arizona State
University].

Full 3.4 kilometer width of the mosaic frame from the LROC Image Browser, providing context for the context image [NASA/GSFC/Arizona State University].

Amazingly, the small perched crater is not a simple bowl shape! Instead of having a discrete rim that rings the entire crater, the crater rim exists only along the upslope portion of Hermann B's crater wall. The other half of the crater rim is a mess! Boulders cover the center of the crater, and streamers were ejected downslope. The blocks hint that the bolide might not have been traveling very fast, and maybe it was a block of ejecta from another crater. Because the bolide that created the fresh crater may have been traveling relatively slowly when it impacted into Hermann B's sloped crater wall, the crater did not form a uniform shape!

Stepping back still further, a 35 km-wide FOV of Hermann and Hermann B and the surrounding floor of Oceanus Procellarum, from a LROC Wide Angle Camera (WAC) observation (M150897433 - 643 nm) a little over one year after the Featured Image was swept up, in LRO orbit 7371, January 28, 2011; resolution is 58.8 meters per pixel from 42.27 km, early afternoon incidence angle 57.159° [NASA/GSFC/Arizona State University].

Noted "NSR's," or "Neutron Suppression Regions" from LEND measurements over the first two years of the LRO mission clearly show depths associated with areas in and around the permanently shadowed regions of craters Cabeus and, nearer to the lunar South Pole, Shoemaker and, to a lesser extent, Faustini. Haworth, where the LAMP far UV detector seems to have detected frost, shows little if any neutron suppression. Is the presentation of LEND data highly contrasted, in false color, to appear to be of higher resolution? [NASA].

A quiet controversy has surfaced regarding the usefulness of the Russian-built and managed LEND instrument on-board the Lunar Reconnaissance Orbiter, now approaching its 12,300th orbit of the Moon.

Intended as a sharper-resolution follow-up to neutron flux detection performed by Lunar Prospector (1998-1999) a team of investigators representing four prestigious institutions are expressing doubts about the actual resolution of the LEND Collimated Sensors for EpiThermal Neutrons (CSETN).

“Serious questions have been raised concerning the effectiveness of the LEND CSETN for actually returning a sharper map of the lunar neutron flux,” the team writes in “What is LEND collimated detector really measuring?” a presentation prepared for the 43rd Lunar and Planetary Science Conference (2012), in March.

Cosmic rays of a wide range of energies rain in on the inner Solar System from beyond the Sun’s interplanetary magnetic field, at a more or less constant rate that varies by roughly 100 percent to a peak infall from all directions at solar cycle minima and dropping by half inversely to solar cycle max. As these energetic nuclei bombard the lunar surface the result is a predictable flux of freed neutrons scattered into space. As a detector in low lunar orbit passes overhead these newly space borne neutrons can be related to their origin on the lunar surface.

The presence of hydrogen, in the form of hydroxyl molecules, hydrogen gas or was water ice, in the upper half meter of the lunar surface will absorb or refract some of these neutrons. It was the confirmation of such an apparent detection by Lunar Prospector that gradually convinced many scientists of the otherwise thought unlikely presence of cold- trapped volatiles, perhaps in the form of water ice, near the Moon’s highest latitudes.

But the neutron detection array on-board the highly budget-restricted Lunar Prospector was of very low resolution, and though the detection of hydrogen by that instrument was mostly confined to the lunar poles its detection was not confined directly to permanently shadowed regions, the only place where water ice was believed possible.

The two complementary detectors of the Lunar Exploration Neutron Detector (LEND), flying on LRO, carried high hopes of a great improvement on the Lunar Prospector measurements. The work by Eke, Teodoro and Lawrence, et al., first appearing in Science last fall, “uses the Lunar Prospector results in combination with data from the LEND CSETN to demonstrate that less than 5 percent of the LEND CSETN counts come from the (detector’s actual) field of view.”

A preliminary letter responding to similar critical comments from Lawrence, et al., written by LEND team members I.G. Mitrofanov, et al., was published in Science, February 14, 2011. It can be read HERE.

Image of artificial moon rock sample, measuring about half
millimeter across, made with an electron microprobe at ambient
temperature after the experiment with X-rays. The fragmenta-
tion of the sample occurred when it was extracted from the
small diamond cylinder in which it had been melted under high
pressure and temperature [ESRF/Nature].

Does the Moon still have even a small, warm liquid core? The answer can only be apparent indirectly, behind its dance movements and the combined angular momentum of it juggled components; the Moon’s anisotropy. If, as investigators now claim, the Moon’s outer surface is still shrinking or, in some cases, stretching, other outward evidence of even a small warm and liquid core can only be discovered indirectly. Why, for example, is any evidence of volcanism on the Moon’s surface at least a billion years old?

A science team in the Netherlands claims to have discovered one answer, the natural buoyancy of molten but poorly mixed constituent materials closer to the Moon’s core. The world’s press is reporting their more subtle investigation, using X-rays, with headlines about future lunar volcanism, which contrasts with their own press release and it's secondary headline:

Deep lunar magma is too heavy to produce active volcanoes

"Scientists have now identified a likely reason for this peaceful surface life: the hot, molten rock in the Moon's deep interior could be so dense that it is simply too heavy to rise to the surface like a bubble in water. For their experiments, the scientists produced microscopic copies of moon rock collected by the Apollo missions and melted them at the extremely high pressures and temperatures found inside the Moon. They then measured their densities with powerful X-rays. The results are published in the Journal Nature Geosciences on 19 February 2012.

"The team was led by Mirjam van Kan Parker and Wim van Westrenen from VU University Amsterdam and comprised of scientists from the Universities of Paris 6/CNRS, Lyon 1/CNRS, Edinburgh, and the European Synchrotron Radiation Facility (ESRF) in Grenoble.

"The driving force for vertical movement of magma is the density difference between the magma and the surrounding solid material, making the liquid magma move slowly upwards like a bubble. The lighter the liquid magma is, the more violent the upward movement will be.

"To determine the density of lunar magma, Wim van Westrenen and his colleagues synthesised moon rock in their laboratory in Amsterdam, using the composition derived from Apollo samples as their “recipe”. The pressures and temperatures close to the core of the Moon are more than 45,000 bar and about 1500 degrees. It is possible to generate these extreme conditions with small samples, heating them with a high electric current while squashing them in a press. By measuring the attenuation of a powerful synchrotron X-ray beam at the (European Synchrotron Radiation Facility) in Grenoble, traversing the sample both solid and molten, the density at high pressure and high temperature could be measured.

“We had to use the most brilliant X-ray beam in the world for this experiment because the magma sample is so tiny and confined in a massive, highly absorbing container. Without a bright beam of X-rays, you cannot measure these density variations”, says Mohamed Mezouar from the ESRF.

"The measurements at the ESRF were combined with computer simulations to calculate the magma density at any location in the Moon.

"Nearly all the lunar magmas were found to be less dense than their solid surroundings, similar to the situation on Earth. There is one important exception: small droplets of titanium-rich glass first found in Apollo 14 mission samples produce liquid magma as dense as the rocks found in the deepest parts of the lunar mantle today. This magma would not move towards the surface.

"Such titanium-rich magma can only be formed by melting titanium rich solid rocks. Previous experiments have shown that such rocks were formed soon after the formation of the Moon at shallow levels, close to the surface. How did they get deep into the mantle? The scientists conclude that large vertical movements must have occurred early in the history of the Moon, during which titanium-rich rocks descended from near the surface all the way to the core-mantle boundary. “After descending, magma formed from these near-surface rocks, very rich in titanium, and accumulated at the bottom of the mantle – a bit like an upside-down volcano. Today, the Moon is still cooling down, as are the melts in its interior. In the distant future, the cooler and therefore solidifying melt will change in composition, likely making it less dense than its surroundings. This lighter magma could make its way again up to the surface forming an active volcano on the Moon – what a sight that would be! – but for the time being, this is just a hypothesis to stimulate more experiments”, concludes Wim van Westrenen."

The hybrid Indo-Russian lunar lander with rover segment of ISRO's
Chandrayaan-2 mission has been planned for 2013. Problems with the
Sub-continent's indigenous heavy-booster are reported to be the cause
[ISRO].

If the estimates of space experts are anything to go by, India’s tryst with moon, Chandrayaan-2, may not happen as scheduled in 2013. Prime reason, cited by those in the know, is country’s inability to perfect the cryogenic engine technology.

“Unless you have the cryogenic engine technology, you will not be considered a space faring nation,” K Sasikumar, former head of Liquid Propulsion Centre of Indian Space Research Organization (ISRO) told DNA.

India has perfected the Polar Satellite Launch Vehicle (PSLV) with which it can put only small satellites into the Low Earth Orbit, which is roughly 900 km from the earth. “We need heavy Geosynchronous Satellite Launch Vehicles (GSLV) for injecting heavy communication satellites weighing more than one tonne into the Geo-Synchronous Orbit (GSO), which is 36,000 km from the earth,” said Sasikumar.

Chandrayaan-2 project director Mylswamy Annadurai, however, refused to comment on the issue. “I am not authorized to speak to the media on the project,” he said.

Prototype of Chandrayaan-2 rover, as developed by August 2010.

Though ISRO tried to launch GSLV with an indigenously developed cryogenic engine in 2010, it plunged into the Bay of Bengal. India has launched seven GSLVs from Satish Dhavan Space Centre at Sriharikotta. Six of them were powered by cryogenic engines from Russia.

Though ISRO chairman K Radhakrishnan claimed indigenous cryogenic engine would complete ground tests, a senior ISRO scientist said it will take years for us to fully operationalise and integrate the technology to the GSLV. “It is not an easy job. The fuel is liquid hydrogen and oxidant is liquid oxygen. You have to pump both liquid hydrogen and oxygen to create the energy and thrust needed to lift the heavy mission from the gravitational pull and put the payload into GSO,” said Nambi Narayanan, former chief of India’s cryogenic program.

Both Nambi Narayanan and Sasikumar had to leave ISRO following the 1993 spy scandal following which the cryogenic engine programme suffered a major setback.

“We don’t have right persons in right places in ISRO. No action has been taken over the FAC report [Failure Analysis Committee which went into the failures of two successive GSLV missions in 2010 submitted their findings and recommendations to the ISRO in early 2011] ,” said G Madhavan Nair, former ISRO chairman and an FAC member. He said the Antrix-Devas deal has been projected as a scam only as a diversionary tactic. “Till we perfect the cryogenic technology, we have to pay ARIANE, the European Space Consortium at French Guiana through our nose,” he said.

It is also said nations such as the United States, France, Japan and China do not want India to come up with its engines as they do not want India to challenge their monopoly in launch business. The US charges more than $50,000 per kg to launch a space craft while India would be able to bring down the cost to $18,000 per kg.

Close-up of the "Virtanen graben" field, near the 18.29°N, 180.79°E, on the central meridian of the lunar far side. From LROC Narrow Angle Camera observation M136355592RE (LRO orbit 5228, August 13, 2010; resolution 0.66 meters from 59.85 km). This LROC NAC frame, along with M136362376, were used by Mark Robinson and colleagues at Arizona State University to create a Digital Terrain Model of the Virtanen graben in November 2010. That DTM can be explored HERE.

Images and elevation models from NASA's Lunar Reconnaissance Orbiter (LRO) appear to show the Moon's crust is being stretched, forming miniature valleys in a few small places on the lunar surface. A team of investigators will present their findings at the upcoming Lunar and Planetary Science Conference as evidence that this geologic activity occurred less than 50 million years ago, a very recent time in relation to the Moon's estimated age of roughly 4.575 billion years.

Researchers analyzing high-resolution images obtained by the Lunar Reconnaissance Orbiter Camera (LROC) have shown many small, narrow trenches typically much longer than they are wide, indicating the lunar crust is being pulled apart at these locations. These linear valleys, known as graben, form when the moon's crust stretches, breaks and drops down along two bounding faults. A handful of these graben systems have already been identified across the lunar surface and are cited as evidence the Moon may be shrinking.

"The graben tell us forces acting to shrink the moon were overcome in places by forces acting to pull it apart. This means the contractional forces shrinking the moon cannot be large, or the small graben might never form."

Full width (about 5 km wide) of LROC NAC DTM"Virtanengraben 1;" the small rectangle is the field of view seen in the image above [NASA/GSFC/Arizona State University].

The weak contraction suggests that the moon, unlike terrestrial planets, did not completely melt in the very early stages of its evolution. Rather, observations support an alternative view that only the moon's exterior initially melted forming an ocean of molten rock.

In August 2010, the team used LROC images to identify physical signs of contraction on the lunar surface, in the form of lobe-shaped cliffs known as lobate scarps.

The scarps are evidence the moon shrank globally in the geologically recent past and might still be shrinking today. The team saw these scarps widely distributed across the moon and concluded it was shrinking as the interior slowly cooled.

Based on the size of the scarps, it is estimated that the distance between the moon's center and its surface shrank by approximately 300 feet. The graben were an unexpected discovery and the images provide contradictory evidence that the regions of the lunar crust are also being pulled apart.

"This pulling apart tells us the moon is still active," said Richard Vondrak, LRO Project Scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland. "LRO gives us a detailed look at that process."

As the LRO mission progresses and coverage increases, scientists will have a better picture of how common these young graben are and what other types of tectonic features are nearby. The graben systems the team finds may help scientists refine the state of stress in the lunar crust.

"It was a big surprise when I spotted graben in the far side highlands," said co-author Mark Robinson of the School of Earth and Space Exploration at Arizona State University, principal investigator of LROC. "I immediately targeted the area for high-resolution stereo images so we could create a three-dimensional view of the graben. It's exciting when you discover something totally unexpected and only about half the lunar surface has been imaged in high resolution. There is much more of the moon to be explored."

Updated map of lunar graben, lobate scarps and further more recent topographic features broadly hinting Earth's Moon is not "dead," as once assumed, but geologically active [NASA/GSFC/DLR/Smithsonian CEPS/Arizona State University].

Monday, February 20, 2012

The Apollo 11 lunar module Eagle ascent stage, carrying Neil Armstrong and Buzz Aldrin as seen by command module pilot Michael Collins, as the two spacecraft prepare to rendezvous and dock over the eastern limb of the Moon. An immediately iconic image even though the photograph went unseen by the public for many days after the expedition returned to Earth. In addition, the image was not available in high resolution until remastered into digital format 30 years later [NASA/JSC/ALSJ].

We watched it from Boy Scout summer camp. The only TV set around was in the mess hall. They propped it up on a counter, made popcorn and keep fiddling with the antenna. A blob of aluminum foil squeezed and shaped just so finally did the trick. We had a picture and just in the nick of time. The door to the Lunar Excursion Module (LEM) opened, Neil Armstrong climbed down the ladder and hopped off into the powdery lunar soil.

The picture was fuzzy but the moment was crystal clear. You’ve seen it. One small step for (a) man … etc. (*See footnote below)

The impact of American space exploration in the 1960s, 70s and beyond cannot be denied. It wasn’t just the fantastic scientific breakthroughs in communications, rocketry and breakfast drinks (Tang!), it was the cultural import of being people who really learned how to fly. We were so mighty we left the planet.

The nation’s greatest heroes in that period were astronauts, rather than actors of sports stars. None was bigger than John Glenn, who, 50 years ago this week, became the first human to orbit the Earth. The achievement seems a little lackluster in retrospect, but at the time it was a huge deal. Everybody knew the name and America’s next generation sought to emulate him. Popular entertainment reverberated with space-based plots and ideas. It seemed like us students studied the Solar System and all that went with it for well more than half the year.

Riding with the Russians

And yet, here we are today in America, without a working starship or even a rocket for that matter. All the Americans who will go into space until at least the end of this decade will ride Russian, using tickets that cost $60 million a pop.

This sounds like yet one more sign of the apocalypse. Though we’re still committing a fair amount of cash to the space program — President Obama’s budget calls for spending $17.7 billion on NASA next year — it has faded from the frontal lobes of the national consciousness. This is not, as some might suspect, more effects of the Great Recession. Space program spending, measured in real dollars, has plummeted since its mid-1960s peak, when it represented almost 5 percent of governmental spending. The space agency’s budget recovered briefly — and only incrementally —in the late 1980s, but has been in slow decline since.

This has more to do with space fatigue than economic pressures. After conquering the moon, NASA’s mission became (comparatively) more mundane. While space launches were still noted and viewed, the missions themselves weren’t edge-of-the-seaters. We stopped sending Walter Cronkite to Houston to report live from Mission Control, when all that was happening was that the Columbia was making another orbit, conducting tests on gamma rays and helium isotopes.

Part of that is our growing distraction due to the ever-increasing media bombardment. A bigger part may be just reality itself. As the idea of human space exploration has matured (realizing, of course, that we’re probably still in our infancy) the next steps have been, well, humongous leaps for mankind. Launching monkeys into space, sending a man up, sending a man into orbit, sending a man some 240,000 miles away to the moon … the progression there made sense. But after 5-6 lunar trips, public interest (which is critical to funding) waned. The next obvious target was, and is Mars, but serious Martian adventures require an expense and contain a complexity of magnitude that dwarfs all that came before. Because of the necessities of launch widows, etc., astronauts headed to the Red Planet would need something on the order of 3 million tons of supplies, or 600 times the capacity of our biggest existing shuttle. And the shuttle currently can’t be any bigger because we don’t have a rocket powerful enough to push it out of our atmosphere.

The current budget includes expenditures on research for bigger rockets and other technology, but the bulk will be spent on what NASA calls “Earth Science.” These missions look at the Earth’s surface from orbital perches and help us figure out answers to questions about global warming and crop rotation.

Important stuff that, but it was more fun when there was something in the mess hall to watch.